Metal-Enhanced Upconversion Luminescence Tunable through Metal Nanoparticle鈥揘anophosphor Separation
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- 作者：Marjan Saboktakin ; Xingchen Ye ; Soong Ju Oh ; Sung-Hoon Hong ; Aaron T. Fafarman ; Uday K. Chettiar ; Nader Engheta ; Christopher B. Murray ; Cherie R. Kagan
- 刊名：ACS Nano
- 出版年：2012
- 出版时间：October 23, 2012
- 年：2012
- 卷：6
- 期：10
- 页码：8758-8766
- 全文大小：584K
- 年卷期：v.6,no.10(October 23, 2012)
- ISSN：1936-086X
文摘
We have demonstrated amplification of luminescence in upconversion nanophosphors (UCNPs) of hexagonal phase NaYF4 (尾-NaYF4) doped with the lanthanide dopants Yb3+, Er3+ or Yb3+, Tm3+ by close proximity to metal nanoparticles (NPs). We present a configuration in which close-packed monolayers of UCNPs are separated from a dense multilayer of metal NPs (Au or Ag) by a nanometer-scale oxide grown by atomic layer deposition. Luminescence enhancements were found to be dependent on the thickness of the oxide spacer layer and the type of metal NP with enhancements of up to 5.2-fold proximal to Au NPs and of up to 45-fold proximal to Ag NPs. Concomitant shortening of the UCNP luminescence decay time and rise time is indicative of the enhancement of the UCNP luminescence induced by resonant plasmonic coupling and nonresonant near-field enhancement from the metal NP layer, respectively.